The production of compounds derived from intramolecular photocgcloaddition reactions upon Diels-Alder adducts has received considerable attention, but assignment of the NMR spectra of the photoaddition products has proved problematic, rendering structural determination difficult. This paper reports the complete assignments of the proton and carbon NMR spectra of 11.1 I-dimethoxypentacyclol S.~.0.02~6.0"".0".9 lundecan-&one and the assignment of the spectra of pentacyclo 1 5.4.0.02~6.0'~'0.05~9

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The electronic and optoelectronic behavior of white organic light-emitting devices (OLEDs) based on blue (FIrpic) and red [Ir(piq)2(acac)] phosphorescent dyes doped into the same layer of a polyvinylcarbazole (PVK) host are reported. The conductivity of all the OLEDs studied appeared to be dominated by space-charge injection effects, exhibiting a current I versus voltage V dependence of the form I∝Vn, with n≈7 at applied voltages at which electroluminescence was observed. Systematic studies of the current versus voltage and light-emitting behavior of the OLEDs have identified different excitation processes for the two dyes. It is suggested that electroluminescence from the FIrpic molecules originates by direct transfer of the exciton energy from the PVK to the dye molecules, while the process of light emission from the Ir(piq)2(acac) molecules involves carrier trapping. The efficiency of the devices can be tuned, to some extent, by varying the thickness of the organic film. Luminous efficiencies and luminous power efficiencies of 8 cd A−1 and 3 lm W−1 were measured for these blended-layer OLEDs, with Commission Internationale de l’Eclairage coordinates of 0.35, 0.35.

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